The control of relative humidity level in the interior of aircraft during long flights at high altitude is nowadays almost obligatory so as to improve the comfort of the passengers and the crew. Thus, if the relative humidity is too low, for example below 10%, the passengers and the crew, during long flights, can be subject to unpleasant sensations, particularly drying of the eyes, the nose and the throat. Moreover, for the crew, such humidity can give rise to health problems, such as kidney stones, exfoliation of the skin in the presence of specific irritants.
So as to overcome these drawbacks, it is usual nowadays to provide aircraft with humidifiers designed to permit maintaining a relative humidity of the order of 15% to 30% within the cabin and thus to improve the comfort of the passengers and the crew.
Known humidification devices such as particularly are described in U.S. Pat. No. 4,272,014, inject droplets of water into a current of warm air from a turbomachine of the aircraft. The principal drawback of such devices resides in the fact that they do not permit guaranteeing total evaporation of the water. Because of this, there can be phenomena of condensation of water on cold surfaces of the aircraft, which gives rise to the risk of corrosion of the structure of said aircraft.
Moreover, the solution which would permit overcoming this drawback, consisting in using an injection device provided with a small cross section atomizing nozzle so as to ensure complete atomization of the water, leads to rapid obstruction of the atomizing nozzle, resulting in the form of mineral deposits. Because of this, the injection device must be cleaned frequently, which gives rise to high maintenance costs.
Moreover, with such injection devices, the mineral particles can be entrained in the heating/air conditioning circuit and give rise to problems of corrosion. For this reason, the injection devices are provided with a filter which however has the drawback of requiring frequent cleaning and hence increasing maintenance costs.
Finally, such injection devices have the drawback of being adapted to be the source of contamination by diffusion through the cabin of bacterial contaminants or viruses, contained in the water.